With the unceasing development of electronic technologies, a trackball, a scroll wheel and other rolling devices have been widely applied to a wheel mouse, a steering wheel of a game machine and other rolling type input apparatuses. At present, the rolling type input apparatuses are used in various terminal products, such as mobile telephones and computers, to control the position of a cursor on a screen.
Compared to a five-way navigation, the trackball is more flexible in direction, and occupies less surface area of a casing. Compared to a two-way navigation, a scroll wheel of a wheel mouse makes it easier for users to change the direction of a cursor.
As shown in FIG. 1, a trackball 11 which is popular in a rolling device is now taken as an example to illustrate the basic operational principle of the trackball 11 set in electronic equipment provided with a rolling type input apparatus in the prior art.
A Hall component is provided in the middle (inside) and in each of the up, down, left and right directions of the trackball 11, respectively. When a user rolls the trackball 11, the Hall components will detect a rolling direction and rolling distance (or angle) of the trackball 11, and generate corresponding interrupts. Software 12 in the rolling type input apparatus may identify the number and directions of the interrupts. When the number of the interrupts in a direction reaches a threshold value set in the software 12, the software 12 will respond to the interrupts once by transmitting one moving event (or called key-press event) signal, and report the moving event signal to a processor 9 in the electronic equipment. After detecting one reported moving event signal, the processor 9 will control a cursor 80 to move on a screen 8 once. Accordingly, one moving event is finished.
The sensitivity experienced by the user is generally what distance (or angle) is rolled by the user for the trackball 11 to activate a moving event, namely, to send a moving event signal to the processor 9 which controls the cursor 80 to finish one moving event. The relationship between the rolling distance of the trackball 11 and the number of interrupts has been determined when hardware set is finished. Therefore, the sensitivity of the trackball 11 may be changed usually by setting a corresponding threshold value in the prior art.
The requirements on the sensitivity are different because of the difference of users' palms and move habits. In the prior art, the sensitivity of the rolling type input apparatus is adjusted by the way of setting a threshold value of the interrupt responded to by the software 12 in the rolling type input apparatus as shown in FIG. 1. To satisfy different requirements of users, the rolling type input apparatus with the trackball 11 in the prior art provides an easy function for setting sensitivity. The users set a value of sensitivity manually, and then the software 12 will set threshold value based on the value set by the users. The higher the value of sensitivity is set by the users, the lower the threshold value is set by the software 12, and the longer distance the cursor 80 is moved on the screen 8 when a certain distance (or angle) is rolled by the users. For example, the trackball 11 generates 6 interrupts by rolling for one revolution; if the threshold value is set to 3, then the software 12 considers that a user presses a direction-key twice (namely, 6/3) after the user rolls the trackball 11 for one revolution, and reports two moving events to the processor 9, namely, to activate two moving event signals; if the threshold value is set to 1, then the software 12 considers that the user presses the direction-key six times (namely, 6/1) after the user rolls the trackball 11 for one revolution, and reports six moving events to the processor 9.
However, it has at least the following problems.
Since sensitivity is a subjective index which can not easily be quantified, users often fail to identify the precise sensitivity suitable for their own. The most suitable sensitivity may be found by personally modifying and attempting, which requires a user's long-term use and several attempts. Since the parameters reflecting the sensitivity of the trackballs are different among different brands or types of electronic equipment, the user has to use a new brand or type of electronic equipment quite a long time and makes several attempts to identify the suitable parameters when using the new brand or type of electronic equipment. Therefore, setting the sensitivity is troublesome.